Feeding mechanism



July 31, 192s.

C. F. OSGOOD FEEDING MECHANISM Filed May 24, 1923 aff-Wil,

Patented July 31, 1928.

N UNITED STATES PATENTV OFFICE. l

CHARLES F. OSGOOD, OF CLAREMONT, 'NEW HAMPSHIRE, ASSIGNOR 'I'OV SULLIVAN MACHINERY COMPANY, A. CORPORATION OF MASSACHUSETTS.

FEEDING MECHANISM.

Application led May 24,

mechanism having improved controlling means. `A further object of my invention is to provide an improved feeding mechanism for pressure fluid rock drills having improved means for controlling the operation thereof. A still furtherV object of my invention is to provide an automatic-*air feed control for the feeding mechanism of pressure fluid rock drills of the percussive type whereby the air feed is automatically controlled in accordance With thenature of the drilling encountered. Other objects and advantages Vof my invention Will hereinafter more fully appear. e Y In the accompanying drawings I have shown for purposes of illustration two forms which my invention may assume in practice.

In'these drawings, Y Fig. 1 is a sideelevation, partially broken away to facilitate illustration, of a drilling mechanism incorporating -my improved controlling mechanism.

Fig. 2 is a side elevation, partially in central longitudinal section, of Fig. 1.

Fig. 8 is a detail sectional view, similar to that of` Fig. 1, showing a modified form of kmy invention. In the illustrative form of my invention shown in Figs, 1 and 2 I" have shown the same employed in a stopper drilling mechanism of standard form, generally designated 1, and which comprises a drilling motor 2 and a feeding mechanism 3. The-drilling motor is herein of the valveless percussive type adapted to percussively actuate a drill steel 4 carried in a chuck 5 in the front end of the drilling motor. The feeding mechanism 3 comprises a feed cylinder and a feed piston' 7 disposed therein having a piston rod 8 suitably secured thereto and terminating ina point 9 adapted to engage a suitable abutment, or support, during drilling, herein the mine bottom. s

Interposed between the drilling motor'Q and the feeding mechanism 3 is a head block 10 which incorporates my improved control- 1923. Serial No. 641,094.

ling mechanism. The feeding mechanism,

the head block, and the drilling motor parts are rigidly held in position by side rod connections'll, in a Well known manner. Suitably secured to the head'block l() is a handle 12 extending laterally from the drill and which is employed to rotate the drill steel, if automatic rotation is not desired, and to support the drill during the drilling opera'- tion Whether the latter is automatically or manually rotated. Arranged Withinv a boss formed integral with the head block is a throttle valve 13, provided with a controlling handle 14, through Which pressure fluid is supplied to the drilling motor and to the feeding mechanism byk means of a hose connection 15 from any suitable source of supply.

In the drilling operation, if a soft spot, or cavity, is encountered, the power of the air feed should ordinarily be reduced to enable the machine to operate in its most efficient manner. To accomplish this I have provided adjacent the throttle valve 18my improved automatic feed controlling mechanism, generally designated 16, and comprising a valve 17 having a conical or tapered head 18 which graduates the admission of pressure fluid as hereinafter described. The head 18has a slot19 cut in its taperedside so that when the valve is seated a small amountof pressure fluid may leak past to the feedl cylinder 6. At the opposite end of the valve 17 is provided a piston head 20 disposed in a pressure tight-'chamber 21 which communicates with the interior of the feed cylinder 6 bymeans of a 'passage' 22. To prevent the pressure building up on the 'other side of the piston head .2() a leak port 28 'is provided exhausting this end of4 the chamber to .the atmosphere. Within the head block 10 is a constant pressure chamber 24 from which pressure fluid is distributed to thefee'd cylinder. Pressure fluid is conducted to the chamberi by Way of a port 25 which communicates with a bore 26 axially disposed in the throttle valve 13. The bore 26 communicates With'the pressure suppl by Wa of a port 26. Slidable ink the bore 26 is a valve 27 under control of a lever 28 arranged Within the handle 14. When it is` desired to manually control the Vair feed, the lever 28 is Amanipulated by the operator, seating, or partially seating, the

\ invention is as follows.

valve 27. Leading from the pressure chamber 24;, under the control of the valve 17, is a passage 29 communicating with the feedV cylinder. The chamber 2li is suitably closed by a plug through Which entends an ad1 instable follower31 by Which the pressure on a spring 32, acting on the valve 17, may be adjusted. The type of valve shown is for illustrative purposes only, the particular type of valve being immaterial.

'lhe mode of operation of this form of my improved device is as follows. The point 9 of the feed piston 7 is placed against an abutment a suitable distance from the Working face, the drill being supported by the handle 12. The operator opens the throttle valve 13 admitting fluid pressure to the drilling motor and the chamber 2l. The pressure in the chamber 2l acts on the surface of the head 18 of valve 17 moving it to its seat, the pressure at this time being` low in the feed cylinder. Pressure fluid then leaks through the slot 19 gradually building up the pressure in the feed cylinder (i, the port 22, and the chamber 21, mov- Aing the piston head 20 sliehtlT to the left,

admitting more pressure 'lluid to the feed cylinder by Way of port 29, and as the drilling motor 2 ydeepens the hole inv the usual manner the drill is fed forward, the cylinder G moving relative to the piston 7. lf a soft spot, or cavity, is encountered, the drill moves rapidly forward materially reducing the pressure Within the feed cylinder and consequently in the chamber 21. The pressure Within the chamber 24.- then overcomes the pressure in the chamber 2l seating the valve 18 and subsequently retarding the feed. When feeding movement is again resisted, theV controlling valve returns to ts initial position. if rom the foregoing description it is clearly apparent that the valve 1T will automatically control the strength of feed in accordance with the nature of the drilling. Alihen it is desired to manually control the feed, the lever 28 is grasped by the operator moving` the valve 2'? to the ight, cutting ofi' the pressure supply to the chamber 24 and subsequently rotar-ding the feed.

ln the form of my invention shown in Fig. 3, I have shown a device similar to that in Figs. 1 and 2 except that a valve 18 is employed provided with a groove 33 slidable in a bore 34. Communicating With the bore 34 is a pair of ports 35 and 36, respectively, the `former leading to the feed cylinder (i While the latter leads to .the atmosphere.V rl`he passage 29 communicates directly with the throttle valve 13.

The mode of operation of this form of my 4 l/Vhen the pressure drops Within the `feed .cylinder 6,'as when softdrilling. ora cavity is encountered, the pressure drops in the chamber 21 and the spring 32 then forces the valve 18 to the right., opening communication between the ports 35, 36 and venting the feed cylinder to the atmosphere, thereby retarding the feed.

ldlhile l have in this application specifi cally described two forms which my inven- :tion may assume in practice, it Will be understood that these forms of the same are shown for purposes of illustration and that the invention may be modified and embodied in various other forms Without departing from its spirit or the scope of the appended claims.

l/Vhat l claim as new and desire to secure by Letters Patent is:

l. ln a drilling apparatus, the combination with a drilling motor, pressure fluid actuated feeding means therefouand means for supplying pressure fluid to the latter, of pressure fluid controlled means controlled by pressure variations in said feeding means for automatically arresting` an abnormal rate of feeding movement When the resistance on said feeding means is decreased.

2. ln a drilling apparatus, the combination with a drilling motor, pressure fluid actuated feeding means therefor, and means for supplying pressure fluid thereto, of means automatically responsive to the pressure in said feeding means for arresting an abnormal rate of feeding movement when the resistance on said feeding means is decreased. y

3. In a drilling apparatus, the combination Vwith a drilling motor, pressure fluid actuated feeding means therefor, and means for supplying pressure fluid thereto, of feed control means operative to reduce the flow of pressure fluid to said feeding means automatically governed by the decrease in resistance te feeding movement. y

el. In a drilling apparatus, the combination with a drilling motor, pressure fluid actuated :feeding means therefor, and means for supplying rpressure fluid thereto, of means automatically responsive to pressure conditions in said feeding means for 'reducing` the supply of pressure fluid thereto in accordance with decrease of pressure therein.

5. In a drilling apparatus, the combinationwith a drilling motor, pressure fluid actuated feeding means therefor, and means for supplying pressure duid to the latter, of

means automatically responsive to a decreased resist-ance to feeding movementfor decreasing the fluid flow to said feeding means.

6. ln a drilling apparatus, the combination with a drilling mot-or, pressure fluid actuated feeding means therefor, and means for supplying pressure fluid to the latter, of pressure fluid controlled valve means forautomatically substantially closing the fluid now to said feeding means when the resistance to movement of the latter is suddenly decreased.

7. In a drilling apparatus, the combination with a drilling motor, pressure fluid actuated feeding means there-for, and a pressure fluid supply for the latter, of ay valve foi-initially controlling the flow of fluid from said supply to said feeding means, and automatic means for subsequently controlling said fluid flow, said automatic means being responsive to a decrease in the feeding pressure foi` reducing the flow of fluid from said supply to said feeding means.k

8. Iii a drilling yapparatus, the combination with a drillingl motor, fluid actuated feeding means therefor, and a fluid supply for the latter, of a plurality of manually operable valves for initially controlling the fluid flow to said feeding means, and a pressure fluid actuated valve for automatically subsequently controlling vsaid fluid flo-w, saidy automatic means being responsive to a decrease in the feeding pressure for'reducing the flow of fluid from said supply to said feeding means.

9. In av drilling apparatus, the combination with a drilling ino-tor, fluid actuated feeding means therefor, and a fluid supply for the latter, of means for initially controlling the flow of fluid from said supply to said feeding means coinpi'ising a manually operable valve, and automatically fluid actuated valve means for subsequently` controlling the fluid flow to said feeding means, said automatic means being responsive to a decrease in the feeding pressure for reducing the flow of fluid from said supply to said feeding means, said automatic means being operable independently of said man-` ual means.

10. In a drilling apparatus, the combination with a drilling motor, fluidactuated feeding means therefor, and a fluid supply for the latter, of means for controlling said fluid supply includ-ing a valve having its op- 'posite ends subjected to the pressure in said feeding means and to said fluid supply respectively, said valve being responsive to a decrease in the feeding pressure for interrupting said fluid supply.

l1. In a drilling apparatus, the combination with a pressure fluid actuated drilling motor, pressure fluid actuated feeding means therefor, and a fluid supply for said motor and feeding means, of means for primarily controlling the fluid flow to said' supply and said feeding means, supplemental4 cylinder to effect relative movement between the latter and said piston, and automatic Ymeans controlled by the pressure within said feed cylinder to arrest an excessive rate o-f relative movement between said cylinder yand piston vwhen the resistance to feeding movement is suddenly decreased.

13. In a drilling apparatus, the combination with a drilling motor, pressure fluid actuated feeding means therefor, and means for supplying pressure fluid to the latter, of

pressure fluid controlled means automatically operative wlien the resistance to feeding is decreased vto diminish the ratio of feed effecting force to feed resistance.

lll. In a drilling apparatus, the combination with a drilling motor, pressure fluid actuated feeding means therefor, and means for supplying pressure fluid to the latter, of means automatically operative when the resistance to feeding is decreased'to diminish the unbalanced force tending to effect feed- Ving movement.

In testimony whereof I afliX my signature.

CHARLESV F. OSGOOD.

lso 

